Spray the inside of your air fryer basket or tray with a cooking spray that is air-fryer friendly (see notes).
Place frozen onion rings in an even single layer in the air fryer basket or on the trays. It's okay if some of the rings overlap, but try not to stack the onion rings on top of one another. If necessary, work in batches.
Air fry at 350°F for 4-5 minutes. Shake the basket or flip the onion rings over on the tray. Air fryer for another 4-5 minutes until cooked to golden brown crispy perfection. Serve immediately.
Notes
Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat: air fry at 350°F for 2-3 minutes.